Motor vehicle seat

The seat (1) has a mechanism with a transmission rod (16) linked in rotation to a backrest (3) and a support rod (17) linked in rotation to a structure of a vehicle, where the rods are linked with each other. The backrest is rotated towards a seat (2) to rotate the support rod in a fixed position in which the rod (17) is in support against a stop, and to displace the seat (1) towards a predetermined position by the rod (16).